Δ8-Tetrahydrocannabinol, the pyschoactive marijuana derived cannabinoid, binds to the CB1 receptor in the brain and to the CB2 receptor in the spleen. Compounds which stimulate the CB1 receptor have been shown to induce analgesia and sedation, to cause mood elevation, to control nausea and appetite and to lower intraocular pressure (Mechoulam, Cannabinoids as Therapeutic Agents, CRC Press, Boca Raton, Fla. (1986), Fride and Mechoulam, Eur. J. Pharmacol. 231:313 (1993), Crawley et al., Pharmacol. Biochem. Behav. 46:967 (1993) and Smith et al., J. Pharm. Exp. Therap. 270:219 (1994)). Compounds which stimulate the CB2 receptor have been shown to suppress the immune system (Mechoulam, Cannabinoids as Therapeutic Agents, CRC Press, Boca Raton, Fla. (1986), Fride and Mechoulam, Eur. J. Pharmacol. 231:313 (1993), Crawley et al., Pharmacol. Behav. 46:967 (1993) and Smith et al., J. Pharm. Exp. Therap. 270:219 (1994)).